This invention relates generally to radio frequency (RF) transmitters and receivers, and more particularly the invention relates to an RF transmitter/receiver (transceiver) which operates at multiple carrier frequencies.
Wireless transceivers, such as used in cellular phone systems, operate in assigned frequency ranges. Cellular systems in the U.S. operate in the 800-950 MHz range while PCS operates in 1800-2000 MHz. As new frequency bands are assigned, the transceiver must be capable of operating in different frequency ranges. Heretofore, in operating in two or more frequency ranges, two or more frequency RF transceivers have been required, with these transceivers designed for a particular frequency or frequency band. For two frequency bands, this approach essentially doubles the cost of the RF transceiver and also doubles the printed circuit board area, design cycle, and parts count. This is contrary to the need in the wireless market for low cost, small size, and light weight.